Effect of Different Protective Bases on pH Changes and Hydrogen Peroxide Microleakage During Intracoronal Bleaching.

Objectives: This study aimed to evaluate the pH changes and penetration of hydrogen peroxide into radicular dentin when different protective bases were used with and without a bonding agent. Materials and Methods: In this in-vitro experimental study, 70 single-rooted bovine teeth were instrumented and obturated with gutta-percha. The gutta-percha was removed 3mm below the cementoenamel junction (CEJ) and the teeth were divided into seven groups (n=10). In each group, 2mm base (1mm apical to the CEJ) was applied as follows: TheraCal LC, TheraCal LC plus SE Bond, Lime-Lite, Lime-Lite plus SE Bond, Ionoseal, Ionoseal plus SE Bond, and resin-modified glass ionomer (RMGI). The teeth were placed in vials containing distilled water, and pH values and molar concentration of the medium surrounding the teeth were recorded immediately after internal bleaching with 35% hydrogen peroxide. The pH values were also recorded at 1, 7, and 14 days following renewal of the medium. Data were analyzed with t-test, one-way ANOVA, and Kruskal-Wallis test. Results: After bleaching, the medium pH became acidic in all groups. There were no significant differences among groups in the mean pH of the medium after bleaching (P=0.189). Moreover, there were no significant differences among the study groups with respect to hydrogen peroxide concentration (P=0.895). Conclusion: Intra-orifice barriers such as light-cure resin-modified calcium hydroxide, light-cure resin-reinforced glass ionomer, and light-cure calcium silicate can be as effective as RMGI in providing coronal seal during intracoronal bleaching.

The effect of intraorifice barriers (TheraCal LC, Lime-Lite and Ionoseal) on the fracture resistance and failure patterns of endodontically treated teeth submitted to intracoronal bleaching.

Background: The aim of the study was to compare the root reinforcement potential of different light cured intraorifice barriers (TheraCal, lime-lite, Ionoseal and resin-modified glass-ionomer [RMGI] [Fuji II LC]) with or without bonding agent placed in the orifice of endodontically treated and bleached teeth. Materials and Methods: In this experimental in vitro study, single-rooted bovine teeth were instrumented and obturated with gutta-percha. Except the control group, in other specimens, gutta-percha was removed 3 mm under cementoenamel junction. Then, the specimens were divided into seven groups according to the bases was applied: TheraCal LC, TheraCal LC with bonding agent, Lime-Lite, Lime-Lite with bonding agent, Ionoseal, Ionoseal with bonding agent, and RMGI (Fuji II LC). After internal bleaching, the teeth were decoronated. Then, all the groups were subjected to fracture resistance testing using Universal Testing Machine. For evaluating fracture resistance, analysis of variance and Tukey's test were used and for comparing the mode of fracture fisher test was applied in SPSS software. The significance was determined at (α = 0.05) confidence interval. Results: The group of TheraCal LC with bonding agent showed better fracture resistance as compared to the control group (P = 0.004). Although there was no statistically significant difference in the pairwise comparison between the other groups. Conclusion: TheraCal LC with bonding agent can be used as intraorifice barriers with good fracture resistance in endodontically treated and bleached teeth.

Anesthetic Efficacy of Lidocaine/Ketorolac in Inferior Alveolar Nerve Block in Patients with Irreversible Pulpitis: A Randomized Clinical Trial.

OBJECTIVE: The purpose of this randomized, double-blind study was to evaluate the anesthetic efficacy of lidocaine-ketorolac administration by Inferior Alveolar Nerve Block (IANB) in patients with irreversible pulpitis. METHODS: Eighty-eight adult patients received a combination of either one cartridge of '2% lidocaine with 1: 80.000 epinephrine' (Li) plus one cartridge of a mixture of 0.8 mL of the same solution and 1mL ketorolac tromethamine (KT)(30 mg/mL), or one cartridge of Li solution plus one cartridge of a mixture of the same solution and saline. Endodontic access was prepared after fifteen minutes. Anesthetic success was defined as no or mild pain [less than 54 mm on the Heft-Parker visual analog scale (HP-VAS)] during access cavity preparation and initial file insertion. Chi-square test was used for data analysis, and the level of significance was set at 0.05 (P=0.05). RESULTS: Results showed that the success rates were 34.1% and 27.3% for Li-KT and Li-Saline groups, respectively, with no significant difference between the two groups (P=0.48). However, significant decrease of baseline mean VAS pain score of the participants in both groups was found during access cavity preparation or initial file insertion (P<0.05). CONCLUSION: Mixed Li-KT solution did not increase the success rate of IANB injection significantly.

Comparison of Oral Melatonin and Midazolam as Premedication in Children Undergoing General Anesthesia for Dental Treatment.

BACKGROUND: Dental anxiety is prevalent in children. This condition may cause uncooperative behavior and need a treatment under general anesthesia. The perioperative period, especially for children, is a stressing event. Premedication is commonly used to reduce perioperative anxiety and facilitate the induction of anesthesia. METHODS: 132 children candidates for dental treatment under GA were enrolled in this study and randomly divided into 3 groups. Oral melatonin, midazolam, and normal saline were administered as premedication. Patient's sedation score before GA, the ease of intravenous line establishment, patient's need for painkillers, and duration of recovery were evaluated and compared. RESULTS: Regarding the sedation score and response to IV access establishment, comparisons showed statistically significant differences between melatonin and midazolam groups (P < 0.05) as well as between midazolam and placebo groups (P < 0.001). The difference between melatonin and placebo groups was not significant (P > 0.05). The need for painkiller administration was statistically different between midazolam and placebo, melatonin and placebo, and midazolam and melatonin groups (P < 0.05). A statistically significant difference was also found between melatonin and midazolam as well as between melatonin and placebo groups (P < 0.05) with regard to the recovery duration while no significant difference was observed between midazolam and placebo groups (P > 0.05). CONCLUSION: Midazolam is superior to melatonin for premedication regarding the patients' sedation score before anesthesia and the ease of IV access establishment. Premedication with midazolam decreases the need for painkillers and increases the rate of recovery in children undergoing GA for dental treatment.